Question

why did some people in 18 century Europe think that print culture would bring enlightenment and end despotism

Answer 1

you see everyone in the 18 century was not as educated as you and I are today so for them to understand things, prints played a vital role
further prints expressed the filings of the painter and were more attractive with no doubt than the written works

Answer 2

The easy and cheap availability of the print culture meant that literacy would no longer be restricted to the upper classes and can be accessed by anyone.